High accuracy navigation solutions generally require the ability to fuse input from multiple sensors so as to make use of all available navigation information. Various types of ranging sensors are being developed for inclusion in navigation systems. For example, radio frequency ranging, sonar, and optical ranging are all being used in navigation systems. In many systems, multiple ranges to known locations (at least three) that are received at the same time (or in quick succession) may be used to triangulate a position. It is more difficult to fuse information into the navigation solution from single ranges to the same or different known locations spread out in time.